SMA WITH INSTRUCTOR FLYING HAS ALTDEV ON IFR FLT PLAN.

Narrative

CRUISING AT 90 KIAS; HAVING RECENTLY CLBED THROUGH THE CLOUD LAYER WITH NO ICING; I PASSED INTO THE TOP OF A CLOUD AND STARTED TO PICK UP MODERATE RIME; I HAD JUST BEEN HANDED OFF TO ZTL BY ZME ON 123.6 (THIS IS WHAT I HEARD AND CALLED BACK WITH NO CORRECTION). I ALMOST ALWAYS WRITE DOWN NEW FREQS; AND I DID WITH THIS ONE; BUT I HAD NOT WRITTEN DOWN THE LAST MEMPHIS FREQ. I TRIED TO CALL ZTL; BUT GOT NO RESPONSE. THE CLOUDS WERE COMING UP TO GET ME. I DECIDED TO CLB TO STAY ON TOP; OUT OF THE ICE. I LEFT MY ASSIGNED ALT OF 9000 FT AND ENDED UP AT 10200 FT WITH THE BELLY OF THE PLANE SKIMMING THE TOPS. WHEN I FINALLY REGAINED RADIO CONTACT WITH ATL; I WAS APPROVED FOR 10000 FT. SOON I NEEDED 11000 FT AND GOT IT. COMING UP ON 1 PARTICULARLY HIGH RIDGE IN THE CLOUDS; I LET THE AIRPLANE DRIFT UP TO 11400 FT JUST LONG ENOUGH TO TOP THE RIDGE AND SLIDE BACK DOWN THE OTHER SIDE. I ELECTED NOT TO ADVISE ATC OF THIS DEV BECAUSE IT WAS SO SLIGHT AND THE CTLR SEEMED RATHER BUSY AT THE TIME. JUST AS I TOPPED THE CLOUD. THE CTLR ADVISED ME OF THE LCL ALTIMETER SETTING AND SLIGHTLY LESS THAN POLITELY REMINDED ME OF MY ASSIGNED ALT OF 11000 FT. I REPLIED THAT I WAS ON MY WAY BACK DOWN AT THE TIME. END OF STORY. CONDITIONS: MINUS 5 DEGS CENTIGRADE; WINDS 290 AT 35 KTS; VISIBILITY UNLIMITED ON TOP. I HAVE LITTLE TO NO EXPERIENCE WITH ICING AND AVOID IT LIKE THE PLAGUE. THE PLANE HAS NO DE-ICE. I WAS IN GREAT HEALTH; RECENTLY FED; COMFORTABLY WARM; AND ENJOYING THE FLT. (NO UNDUE STRESS.) PROB AROSE WITH HIGHER THAN EXPECTED CLOUDS AND NOT ENOUGH PERFORMANCE ABILITY IN THE AIRPLANE. NO REAL BAD SIT; BUT A DEV THAT I COULD HAVE HANDLED BETTER BY COM WITH THE CTLING AUTH. PROPER FREQ WAS 133.6.